Significant accounting policies (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011
Accounts Receivable [Abstract]
Allowance for doubtful accounts	$ 116,000		$ 116,000		$ 20,000
Provision for doubtful accounts			119,000
Accounts receivable charge-offs			23,000
Revenue Recognition [Abstract]
Net sales returns provision	88,000	22,000	233,000	159,000
Provision charges	135,000	0	161,000	102,000
Fair value of financial instruments [Abstract]
Fair value of short term and long term convertible debt	4,667,000		4,667,000
Fair value of warrants issued in conjunction with placement fees	9,000		9,000
Computation of basic and diluted net loss per share [Abstract]
Net loss	$ (4,219,372)	$ (1,765,723)	$ (6,057,092)	$ (7,616,791)
Denominator for basic earnings per share - weighted average shares (in shares)	84,493,164	73,767,674	84,091,014	72,082,605
Effect of dilutive securities: Stock options and warrants outstanding and convertible debt (in shares)	0	0	0	0
Denominator for diluted earnings per share - weighted average shares adjusted for dilutive securities (in shares)	84,493,164	73,767,674	84,091,014	72,082,605
Loss per common share - basic and diluted (in dollars per share)	$ (0.05)	$ (0.02)	$ (0.07)	$ (0.11)
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)			22,589,158	21,001,417
Outstanding Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)			12,642,833	10,355,000
Outstanding Warrants [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)			3,241,668	8,096,417
Convertible Debt, promissory notes [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)			5,313,133	0
Convertible Line of Credit with Related Party [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)			1,391,524	1,300,000
Convertible Debt, Acquisition [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)			0	1,250,000